Follow plate for dispensing material

ABSTRACT

The combination of a generally cylindrical receptacle for flowable products and a follow plate disposed within the receptacle for applying pressure on the flowable contents to force the material through an outlet opening in the lower end of the receptacle. The follow plate is made of a suitable flexible plastic material and comprises a generally annular disc having a tapered peripheral flange extending axially upwardly and radially outwardly therefrom. The flange has a major diameter sufficiently greater than the inner diameter of the receptacle to remain in sliding sealed engagement with the inner wall of the receptacle during axial movement of the follow plate toward the lower end of the receptacle, and a minor diameter which is substantially less than the major diameter to provide a clearance space at the minor flange diameter for clearing any dents or bumps on the inner wall of the receptacle. The flange also desirably has a taper in excess of 10* to permit substantial cocking of the follow plate within the receptacle while still maintaining line contact between the flange at the major diameter thereof and the inner wall of the receptacle to avoid wedging of the follow plate within the receptacle.

i United States Patent 1191 Klfer Nov. 4, 1975 FOLLOW PLATE FORDISPENSING MATERIAL [75] Inventor: David E. Kifer, Parma, Ohio [73]Assignee: Oatey Co., Cleveland, Ohio [22] Filed: Sept. 10, 1973 [21]Appl. No.: 395,620

Related US. Application Data [62] Division of Ser. No. 243,616, April13, 1972, Pat.

Primary ExaminerStanley H. Tollberg Assistant Examiner-Larry H. MartinAttorney, Agent, or Firm--Donnelly, Maky, Renner & Otto ABSTRACT Thecombination of a generally cylindrical receptacle for flowable productsand a follow plate disposed within the receptacle for applying pressureon the flowable contents to force the material through an outlet openingin the lower end of the receptacle. The follow plate is made of asuitable flexible plastic material and comprises a generally annulardisc having a tapered peripheral flange extending axially upwardly andradially outwardly therefrom. The flange has a majordiameter-sufiiciently greater than the inner diameter of the receptacleto remain in sliding sealed engagement with the inner wall of thereceptacle during axial movement of the follow plate toward the lowerend of the receptacle, and a minor diameter which is substantially lessthan the major diameter to provide a clearance space at the minor flangediameter for clearing any dents or bumps on the inner wall of thereceptacle. The flange also desirably has a taper in excess of 10 topermit substantial cocking of the follow plate within the receptaclewhile still maintaining line contact between the flange at the majordiameter thereof and the inner wall of the receptacle to avoid wedgingof the follow plate within the receptacle.

7 Claims, 6 Drawing Figures 413 FOLLOW PLATE FOR DISPENSING MATERIAL I Afurther object is to provide such a follow plate which is lesssusceptible to jamming within the can or ing US. application Ser. No.243,616, filed Apr. 13,

1972. now US. Pat. No. 3,790,038, granted Feb. 5, I974.

BACKGROUND OF THE INVENTION The present invention relates generally asindicated to a follow plate or piston for dispensing fluid products froma receptacle such asa can ordr um, and more particularly to certainimprovements in such a follow plate to prevent the follow plate fromhanging up within the can and obtain maximum removal of material fromthe can.

The follow plate of the present invention is designed to be disposedwithin the receptacle in pressure contact with the material to bedispensed for forcing the material through an outlet opening at one endof the receptacle. Conventional follow plates of this general type areusually made of metal and oftentimes become wedged against movementwithin the receptacle during tilting of the container or because of adent or other obstruction in the wall of the container.

The type of receptacle with which the present invention is primarilydesigned to be used is a metal can or drum whose inner diameter isusually not very uniform throughout its length, and the drum can also befairly easily dented. The outlet opening for the material also usuallyhas a threaded coupling which is recessed within the lower end of thecan to permit stacking of the cans one on top of the other. A typicalreceptacle might be a 5 gallon can containing a flowable material suchas a plastic car body filler material.

Because the outlet connection for the receptacles are usually recessedwithin an end of the receptacles to permit stacking, it is a problem toobtain complete removal of the material being dispensed, particularlythe material surrounding the recessed outlet connection. In addition,whenever the container is tilted as when attaching a valved conduit tothe outlet connection, the resulting flow of material within the can maycause the follow plate to become wedged against movement within the can.This is especially possible when using a conventional metal follow platehaving a cylindrical or nearly cylindrical flange portion which issubstantially inflexible and easily jams against movement with onlyslight cocking.

Another drawback of conventional metal follow plates is that they do notreadily ride over bumps or dents in the side walls of the cans, and thusare apt to get hung up in the cans. Most internal can diameters are alsonot ordinarily uniform throughout their lengths, and accordingly a metalfollow plate which may have a proper close sliding fit in one portion ofthe can is not likely to have a proper sliding fit in all portionsthereof.

SUMMARY OF THE INVENTION- With the foregoing in mind, it is a principalobject of this invention to provide an improved follow plate fordispensing material from a can or other receptacle.

Another object is to provide such a follow plate which is especiallysuitable for use with metal cans or drums having recessed outletconnections in the lower end thereof to facilitate stacking.

drum and does not become wedged in place when the can or drum is tilted.

A still further object is to provide a follow plate which insures morecomplete removal of the material from the can or drum.

These and other objects of the present invention are obtained by makingthe follow plate of a suitable flexible plastic material having agenerally annular face and a tapered projecting flange portion attachedto the periphery of the face. The tapered flange has a major diameterdefining a free edge for engagement with the inner wall of 'a containerand a sufficiently smaller 'minor diameter to clear any bumps or dentson such inner wall. The taper of the flange is also desirably sufficientto permit substantial tilting of the can and cocking of the follow platewhile still maintaining line contact between the free edge of the flangeand the inner wall of the can, thereby preventing wedging of the followplate against the inner wall of the can.

The face of the follow plate may also be provided with a centralhollowed indentation of sufficient depth to permit it to fit over thecan outlet connection when the follow plate comes to rest against thelower end wall of the can. The face of the follow plate may also be madeslightly conical whereby continued pressure against the follow platewill cause the conical face to deform squeezing the materialtherebeneath toward the center of the can for discharge through theoutlet opening resulting in maximum removal of material from the can.

To the accomplishment of the foregoing and related ends, the invention,then, comprises the features hereinafter fully described andparticularly pointed out in the claims, the following description andthe annexed drawing setting forth in detail a certain illustrativeembodiment of the invention, this being indicative, however, of but oneof the various ways in which the principles of the invention may beemployed.

BRIEF DESCRIPTION OF THE DRAWING In the annexed drawing:

FIG. 1 is a longitudinal section through a preferred form of followplate constructed in accordance with the present invention;

FIG. 2 is a top plan view of the follow plate of FIG. 1;

FIG. 3 is a longitudinal section through a receptacle containing suchfollow plate, showing the location of the follow plate at severalelevations within the receptacle as the material is dispensed from thereceptacle;

FIG. 4 is a longitudinal section showing the operation of the followplate when the can or drum is tilted; and

FIGS. 5 and 6 are partial longitudinal sections showing the follow platewithin the receptacle to illustrate how the follow plate obtainssubstantially complete removal of the material from the receptacle.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in detail to thedrawings, and initially to FIGS. 1 and 2 thereof, there is shown afollow plate 10 in accordance with this invention which is generally inthe form of an annular disc 12 having a peripheral flange 14. The disc12 preferably has a slightly conical face 16 which seats against thematerial to be dispensed when disposed within a receptacle in a mannerto be subsequently described.

The flange 14 extends around the entire outer periphery 20 of the disc12 and is tapered outwardly to a substantial extent terminating in afree edge 22 at the major diameter of the flange which is substantiallygreater than the minor diameter of the flange. In the embodimentillustrated. the flange is tapered at an acute angle a of approximately21.

The slightly conical face 16 of the disc, in about the center thereof,is desirably provided with a hollowed indentation or recess 24 whichextends rearwardly in the same direction as the flange 14. The bottomsurface 26 of the indentation is desirably generally flat and is joinedwith the face 16 by a frusto-conical flange 28 having an inner edge 30integral with the surface 26 and an outer edge 32 integral with the face16.

In the particular embodiment illustrated, the angle b of the conicalface 16 is about 4 from the horizontal, and the flange 28 extends at anangle of about 45 relative to the horizontal. The dimensions of thefollow plate may vary substantially, and are dependent upon such factorsas the size and shape of the can or drum with which the follow plate isemployed. However, a typical follow plate constructed in accordance withthis invention may have a minor flange diameter of approximately 10%inches and a major flange diameter of approximately 1 1% inches,providing a clearance space at the minor flange diameter ofapproximately nine-sixteenth inches all the way around the follow platefor clearing any dents or bumps on the inner wall of the container.Moreover. the follow plate may be made of any suitable flexible plasticmaterial such as polyethylene or polypropylene.

In FIG. 3 there is illustrated a can or drum 34 with which the followplate 10 of the present invention may be employed. The drum 34 isgenerally cylindrical in shape and includes upper and lower ends 36 and38. Because the drum is usually made of metal, it is capable of beingeasily dented, as shown by dent 40 in the side wall or body 42 of thedrum, and the inner diameter of the drum is usually not uniformthroughout its length.

The ends 36 and 38 of the drum 34 may be seal-connected with the body 42either by welding, brazing, or a conventional double seam constructionas shown at 44. An inlet opening 46 in the upper end of the drum permitsan air line to be connected to the drum for pressurizing the drum asschematically shown in FIGS. 3 through 6.

The drum 34 is of course filled with the material 48 to be dispensed,for example, plastic car body filleror other flowable material. Withinthe drum 34 is the fol low plate 10 which seats against the uppersurface of the material to be dispensed, with the conical face 16against the material. The opposite side 18 of the face 16 is exposed tothe pressurized air introduced into the container through the inletopening 46 previously described.

The lower end 38 of the can or drum 34 is substantially flat as shownexcept for the outlet connection 50 which is desirably recessed withinsuch lower end 38 to permit stacking of the cans or drums with the endsof the cans in full contact. In the example illustrated in FIG. 3, therecessed portion 52 of the can is sufficiently depressed with respect tothe end of the can to accommodate a nipple 54 having internal threadsfor engagement by a suitable plug and external threads for attachment ofa cock valve or the like to control the flow of material from the can.

The dimensions of the the major diameter at the free edge 22 of thetapered flange 14 is in sliding sealed engagement or contact with theinner surface of the side wall or body 42 of the can and the minordiameter freely clears any internal dents or bumps in the can body, suchas dent 40. The flange 14 is also sufficiently flexible that the freeedge 22 readily slides over the dents and still provides the desiredwiping action along the inner surface of the can. The same sealingcontact is maintained between the free edge of the follow plate and theinner surface of the drum even though its dimensions may vary somewhatover the length of the drum. Because of the flexibility and shape of theflange, the follow plate will not hang up during movement within thedrum, and: the flange will also readily recover after flexing tomaintain the desired sealing contact or close fit with the inner surfaceof the can.

FIG. 4 illustrates a position assumed by the follow plate 10 when thecan 34 is tilted as it might be to facili-, tate attachment of asuitable conduit 56 to the lower outlet connection 50 of the can. Asshown, substantial tilting of the can and cocking of the follow platecan occur. Despite such cocking of the follow plate within the can, thesubstantial taper of the flange will cause the free edgeof the flange toremain in line contact with the inner surface of the can body andmaintainthe minor diameter of the flange out of contact with such innersurface, thereby preventing wedging contact between the flange and canbody. Accordingly, when the can is righted once again the air pressureacting on the upper surface of the follow plate will also right thefollow plate. Moreover, because the follow plate is made of a flexibleplastic, it will readily give when pressure is exerted on it tending tostraighten the follow plate out thus resisting cocking.

Another advantage of the substantial taper of the flange 14 is that thematerial whichfills the clearance space between the flange and innersurface of the can during operation as shown in FIG. 3 also tends tostabilize the follow plate, and resist cocking thereof.

FIGS. 5 and 6 illustrate the functioning of the follow 1 plate 10 afterengagement of the plate with the lower end 38 of the can. In FIG. 5, theouter periphery 20 of the face 16 is shown at rest against the end 38,with material still trapped between the can end 38 and conical face 16.However, as continued pressure is exerted on the follow plate 10, thefollow plate deforms, flattening the conical face 16 against the can endand causing the material to flow toward the center of the can for discharge through the central outlet connection 50 as shown in FIG. 6. Thedepth of the indentation 24 is sufficientto provide a slight clearancebetween the follow plate and the recessed portion 52 of the can whenthe.

conical face of the follow plate is flattened against the lower end ofthe can as shown.

From the foregoing, it will now be apparent that the follow plate of thepresent invention insures against the follow plate becoming wedged orhung up within the container despite dents or bumps or variations in theinner diameter of the container. The shape of the follow plate also aidsin discharging the last of the material from containers provided with'recessed discharge openings in the lower end thereof.

The embodiments of the invention in which an exclu-.

sive property or privilege is claimed are defined as follows:

follow plate 10 are such that 1. In combination, a generally cylindricalreceptacle for flowable products having upper and lower ends and afollow plate slidably received within said receptacle, said follow platecomprising a generally annular disc having a tapered peripheral flangeextending axially upwardly and radially outwardly therefrom. said flangebeing made of a flexible plastic material and having a major diametersufficiently greater than the inner diameter of said receptacle toremain in sliding sealed engagement with the inner wall of thereceptacle during axial movement of said follow plate therewithin towardthe lower end of said receptacle, and a minor diameter which is at leastone-half inch less than said major di ameter to provide a clearancespace at the minor flange diameter at least one-fourth inch all the wayaround said follow plate for clearing any dents or bumps on such innerwall, said flange having a taper in excess of to permit substantialcocking of said follow plate within said receptacle while stillmaintaining line contact between said flange at the major diameterthereof and the inner wall of said receptacle to avoid wedging of saidfollow plate within said receptacle.

2. The combination of claim I wherein said minor diameter isapproximately l /s inches less than said major diameter to provide aclearance space at the minor flange diameter of approximatelynine-sixteenth inch all the way around said follow plate for clearingany dents or bumps on said inner wall.

3. The combination of claim lwherein said flange has a taper ofapproximately 21.

4. The combination of claim 1 wherein the entire follow plate is made ofa flexible plastic material.

5. The combination of claim 1 wherein said receptacle contains aflowable material such as plastic car body filler, and there are dentsor bumps in the inner wall of said receptacle, said flange at said majordiameter remaining in sliding sealed engagement with the inner wall ofsaid receptacle and said minor diameter providing a clearance space ofsaid dents during movement of said follow plate past said dents asaforesaid.

6. The combination of claim 1 wherein there is a central outlet openingin the lower end of said receptacle for discharge of flowable materialfrom said receptacle. and an inlet opening in the upper end of saidreceptacle for supplying pressurized air to said receptacle above saidfollow plate, such pressurized air acting on the upper surface of saidfollow plate to resist cocking and right said follow plate shouldcocking occur.

7. The combination of claim 6 wherein the clearance space between saidtapered peripheral flange on said follow plate and said inner wall ofsaid receptacle is filled with the flowable material in said receptaclewhich tends to stabilize said follow plate and resist cocking thereof.

1. In combination, a generally cylindrical receptacle for flowableproducts having upper and lower ends and a follow plate slidablyreceived within said receptacle, said follow plate comprising agenerally annular disc having a tapered peripheral flange extendingaxially upwardly and radially outwardly therefrom, said flange beingmade of a flexible plastic material and having a major diametersufficiently greater than the inner diameter of said receptacle toremain in sliding sealed engagement with the inner wall of thereceptacle during axial movement of said follow plate therewithin towardthe lower end of said receptacle, and a minor diameter which iS at leastone-half inch less than said major diameter to provide a clearance spaceat the minor flange diameter at least one-fourth inch all the way aroundsaid follow plate for clearing any dents or bumps on such inner wall,said flange having a taper in excess of 10* to permit substantialcocking of said follow plate within said receptacle while stillmaintaining line contact between said flange at the major diameterthereof and the inner wall of said receptacle to avoid wedging of saidfollow plate within said receptacle.
 2. The combination of claim Iwherein said minor diameter is approximately 1 1/8 inches less than saidmajor diameter to provide a clearance space at the minor flange diameterof approximately nine-sixteenth inch all the way around said followplate for clearing any dents or bumps on said inner wall.
 3. Thecombination of claim 1 wherein said flange has a taper of approximately21*.
 4. The combination of claim 1 wherein the entire follow plate ismade of a flexible plastic material.
 5. The combination of claim 1wherein said receptacle contains a flowable material such as plastic carbody filler, and there are dents or bumps in the inner wall of saidreceptacle, said flange at said major diameter remaining in slidingsealed engagement with the inner wall of said receptacle and said minordiameter providing a clearance space of said dents during movement ofsaid follow plate past said dents as aforesaid.
 6. The combination ofclaim 1 wherein there is a central outlet opening in the lower end ofsaid receptacle for discharge of flowable material from said receptacle,and an inlet opening in the upper end of said receptacle for supplyingpressurized air to said receptacle above said follow plate, suchpressurized air acting on the upper surface of said follow plate toresist cocking and right said follow plate should cocking occur.
 7. Thecombination of claim 6 wherein the clearance space between said taperedperipheral flange on said follow plate and said inner wall of saidreceptacle is filled with the flowable material in said receptacle whichtends to stabilize said follow plate and resist cocking thereof.